Testing of Ultra Fast Response, Durable Co-axial Thermocouples for High Enthalpy Impulse Facilities

James, Christopher M. and Birch, Byrenn J. C. ORCID: https://orcid.org/0000-0003-0625-2455 and Smith, Daniel R. and Cullen, Timothy G. and Millard, Theodore and Vella, Samuel and Liu, Yu and Morgan, Richard G. and Stern, Nathan and Buttsworth, David R. (2019) Testing of Ultra Fast Response, Durable Co-axial Thermocouples for High Enthalpy Impulse Facilities. In: AIAA Aviation Forum 2019, 17 June - 21 June 2019, Dallas, Texas.


Abstract

Fast response heat flux gauges relying on the semi-infinite heat conduction principle have commonly been used to study heat flux in impulse test facilities such as expansion tubes and reflected shock tunnels. For studying the very harsh environments experienced at the stagnation point of entry vehicles, generally metallic gauges such as thermocouples are required to survive the heat loads which may be above ten megawatts per metre squared at peak heating in flight and can be upwards of a hundred megawatts per metre squared in heavily scaled impulse facility testing, which can be challenging for even the toughest heat flux gauges. This paper reports on the design and testing of a new, extremely durable, fast response co-axial thermocouple which was designed at the University of Southern Queensland and has been subjected to over a hundred experiments in the very harsh conditions experienced over a small stagnation point heat flux probe in a free piston driven expansion tube at the University of Queensland. No degradation in the performance of the thermocouple was seen over the more than a hundred experiments and it was shown to maintain its ability to respond to changes in the flow in a matter of microseconds over the whole campaign. Little to no maintenance was required between experiments, even though the thermocouple’s surface temperature had often risen by hundreds of Kelvin by the end of the post-experiment flow. As previous co-axial thermocouples which have been used in these expansion tubes in the past have only survived several experiments before their performance begins to degrade, this is a very positive result.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021)
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021)
Date Deposited: 06 Jun 2022 03:44
Last Modified: 25 Jul 2022 03:56
Uncontrolled Keywords: Expansion tubes; Harsh environment; Heat flux gauges; Reflected shocks; Stagnation point heat fluxes; Stagnation points; Surface temperatures; University of Queensland
Fields of Research (2020): 40 ENGINEERING > 4001 Aerospace engineering > 400106 Hypersonic propulsion and hypersonic aerothermodynamics
Identification Number or DOI: https://doi.org/10.2514/6.2019-3007
URI: http://eprints.usq.edu.au/id/eprint/42046

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